In an LTE-A (long-term evolution advanced, long-term evolution advanced) system, a user equipment (UE) in the LTE-A may use more than one carrier after the carrier aggregation (Carrier Aggregation, CA) technology is applied. Generally, conditions of aggregation may be categorized into three types: continuous CA, discontinuous CA within the same band, and discontinuous CA within different bands.
In the prior art, when a UE moves to the edge of a neighboring cell, the UE generally judges whether the RSRP (Reference Signal Received Power, reference signal received power) value of the neighboring cell is one offset better than the RSRP value of serving cell through measuring RSRP of the neighboring cell; if yes, triggers an A3 event, and submits a measurement report triggered by the event. After receiving the measurement report, the serving cell may start a handover determination procedure.
Usually, a source eNB preferentially selects an eNB with multiple carriers being in the same cell as a target eNB. Using multiple carriers by a UE generally means that the current service data rate of the UE is comparatively high. If the source eNB selects only a single eNB as the target eNB, only one carrier has better channel quality, and other carriers have worse channel quality. Therefore, only the single carrier can be used to support the current service. The current service of the UE may not be well supported, and the user experience of an end user may deteriorate.
In the network topology of the CA, if the UE reports a cell 1 (corresponding to a carrier with the best quality) and a cell 2 (corresponding to a carrier with better quality) as candidate cells in the measurement result, generally, the source eNB may use the cell 1 rather than the cell 2 as the final target cell of the UE, so that the UE is handed over to the target eNB 1 of the cell 1. However, in this case, the UE can use only one carrier, so the data transmission rate is reduced.